rundb: Quick-and-dirty local dev w/MariaDB master-slave

Launch a pair of master-slave MariaDB servers on localhost. The data will be stored in $PWD/master and $PWD/slave.

Server Role	IP	Port	Server ID	Storage
Master	127.0.0.1	3330	3330	$PWD/master
Slave	127.0.0.1	3331	3331	$PWD/slave

Each server has two users, root (no password) and reader (no password).

This is horrifically insecure by default. It's only for internal/local development.

Requirements

• Use Linux or OS X on the local workstation
• Install the nix package manager
  • tldr: Run "curl https://nixos.org/nix/install | sh" as your regular workstation user.

Clean-Start Quick Start

The quickest way to get going is to use clean-start. With one command, this will start an empty master and slave DB with synchronization active. Any data will be (over)written in $PWD/master and $PWD/slave. Usage:

nix-shell https://github.com/totten/rundb/archive/master.tar.gz --command clean-start

You can additionally use CLI tools with these databases; however, the commands should be called with nix-shell, like in these examples:

## Open an interactive bash shell
DB=master nix-shell https://github.com/totten/rundb/archive/master.tar.gz
DB=slave nix-shell https://github.com/totten/rundb/archive/master.tar.gz

## Open an interactive SQL shell (as root)
DB=master nix-shell https://github.com/totten/rundb/archive/master.tar.gz --command mysql
DB=slave nix-shell https://github.com/totten/rundb/archive/master.tar.gz --command mysql

## Open an interactive SQL shell (as reader)
DB=master nix-shell https://github.com/totten/rundb/archive/master.tar.gz --command 'mysql -u reader'
DB=slave nix-shell https://github.com/totten/rundb/archive/master.tar.gz --command 'mysql -u reader'

## Dump a copy of the 'foo' database
DB=master nix-shell https://github.com/totten/rundb/archive/master.tar.gz --command 'mysqldump foo'
DB=slave nix-shell https://github.com/totten/rundb/archive/master.tar.gz --command 'mysqldump foo'

This approach gets you started with one command, but it has several limitations:

• The nix-shell commands are long -- each one reproduces a full Github URL.
• The $PWD/master and $PWD/slave folders are reset everytime you start.
• The log output of both master+slave is combined into one screen.
• The master and slave nodes start together and stop together.
• You can't edit the my.cnf templates.

For a less heavy-handed approach, use the standard quick start.

Standard Quick Start

## Download rundb scripts.
git clone https://github.com/totten/rundb
cd rundb

## Start master DB. (To shutdown, press Ctrl-\)
DB=master nix-shell --command rundb

## Open a new terminal.

## Start slave DB. (To shutdown, press Ctrl-\)
DB=slave nix-shell --command rundb

## Open a new terminal.

## Initiate replication between the two empty DBs
DB=master nix-shell --command init-repl

Configuration files

The configuration files are generated from templates whenever you call rundb. The key files are:

• templates/common/my.cnf: Configuration elements shared by master and slave DB
• templates/master/my.cnf: Configuration file for master DB
• templates/slave/my.cnf: Configuration file for slave DB

More example commands

Each of these examples can be execued with the master or slave.

## Open an interactive bash session
DB=master nix-shell
DB=slave nix-shell

## Open an interactive SQL session (as root)
DB=master nix-shell --command mysql
DB=slave nix-shell --command mysql

## Open an interactive SQL session (as reader)
DB=master nix-shell --command 'mysql -u reader'
DB=slave nix-shell --command 'mysql -u reader'

## Dump a copy of the 'foo' database
DB=master nix-shell --command 'mysqldump foo'
DB=slave nix-shell --command 'mysqldump foo'

## Destroy all state/data
DB=master nix-shell --command 'rundb clear'
DB=slave nix-shell --command 'rundb clear'

## Clear out all master data files. Reinitialize. Run DB in foreground.
## To stop, press Ctrl-\
DB=master nix-shell --command 'rundb clear init run'
DB=slave nix-shell --command 'rundb clear init run'

## As above, but use alternate IP+port.
DB=master nix-shell --command 'rundb clear init run --bind-address=192.168.1.10 --port=9999'
DB=slave nix-shell --command 'rundb clear init run --bind-address=192.168.1.10 --port=9999'